Magnifying reading unit



' W i Y #5 Nov. 2, 1948. s. M. CRESSATY MAGNIFYING READING UNIT 2Sheets-Sheet 1 Filed Feb. 5, 1945 FIG. I

FIG,.3

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GEORGE M. CRESSATY INVENTOR ATTORNEY Nov. 2, 1948. s. M. CRESSATY2,453,064

V MAGNIFYING READING UNIT Filed Feb. 5, 1945 2 Sheets-Sheet 2 FIG. 6FIG, 7

GEORGE u. ORESSATY INVENTOR ATTORNEY Patented Nov. 2, 1948 UNITED STATESPATENT OFFICE MAGNIFYING READING UNIT George M. Cressaty, New York, N.Y. Application February 5, 1945, Serial No. 576,178

6 Claims. 1

This invention relates to optical units and systems used to assist inreading printed pages and more particularly'to magnifying lenses inconjunction with prisms for directing a magnified image toward a reader.

Reading glasses made with spherical and cylin drical surfaces are old inthe art. Some have supports to keep them in the proper position forreading while some are made with elaborate adjustable means for varyingtheir position. The ordinary reading glass, however, has one seriousdefect; when used in the usual manner, the illumination on the page tobe read is generally quite .poor. This is due to several causes: thereading glass itself gets in the way of the source of illumination andcauses a shadow, and the condensing properties of the glass concentratethe available light to form a bright spot close to the portion that isto be read. The combination shadow and bright spot produce anillumination that is tiring on the eyes and makes reading quitedifllcult.

The invention broadly consists of a combination prism and cylindricallens mounted on supporting legs and so aligned as to provide adequateillumination no matter where the source of light is placed. In furtherdetail, a cylindrical lens is formed on top of a prism which may have anangle of 30 degrees between faces. This combination is mountedfwith theplane surface at an angle of about 60 degrees to the reading plane. Aswill be shownhereinafter, this design results in a reading unit that notonly magnifies the reading matter but also bends the light rays towardthe reader and increases the degree of illumination.

One of the main objects of the invention is to improve the design ofreading units so that increased illumination is' present on the readingplane when viewed by the invention.

Another object of the invention is to improve the lightingcharacteristics of a reading unit whereby the illumination will beevenly distributed over the plane to be read.

Another object of the invention is to enable one to read a paper or booklying flat on a table while seated in'a normal position in front of thetable. When the invention is in use it is not necessary to bend directlyover the reading unit to see what is on the reading plane. Reading isdone at an angle.

Still another object of the invention is to enable one to view theentire length of several lines on a page or letter without moving thereading unit.

ill

Another object of the invention is to provide a reading unit with afixed focus. No adjustment is necessary when the unit is in use.

Another object of the invention is to reduce distortion at the edges ofthe field of view.

Other obiects and structural details of the invention will be apparentfrom the following description when read in connection with theaccompanying drawings, wherein,

Fig. 1 is a front view of the reading unit.

Fig. 2 is a cross sectional view of the reading unit taken along line2-2 of Fig.- 1.

Fig. 3 is an end view of the unit.

Fig. 4 is a diagram showing the passage of light rays through thereading unit.

Fig. 5 is a diagram showing how illumination is obtained when the lightis coming from a direction 30 degrees from the plane of the object.

Fig. 6 is a diagram showing how illumination is obtained when the lightis directed 60 degrees from the plane of the object.

Fig. '7 is a diagram showing how illumination is obtained when lightisdirected from a point almost directly above the reading unit.

Fig. 8 is a plan view of the reading unit.

Referring now to Figs. 1, 2, and 3, the reading unit consists of a longtransparent rod II having a curved surface I! on its uppermost portion.In the preferred form (shown in Fig. 2) this surface has a radius of 3inches but this length will vary with materials and degree ofmagnification. While the drawing shows a cylindrical surface, the scopeof the invention is not confined to this limitation. i lens, such asspherical, aspherical, 0 may be used in conjunction with the prism aslong as the lens is large enough to cover a major portion of the surfaceof the prism. In the drawings the lens surface I! is superimposed on theprism surface so that a chord drawn between the edges of the lens makesan angle of about 30 degrees with the reading plane. The chord so drawnis the trace of the sagittal plane of the lens surface.

A plane surface I3 forms the underside of the unit II. This surface isat an acute angle of greater than 15, preferably about 30 degrees fromthe non-parallel sagittal plane of the lens surface I! and hence forms aprism which bends the light toward the reader as will be explainedlater. The angle of surface 13 also acts as a reflecting surface indirecting rays of light to illuminate the characters to be viewed.

-A front surface ll makes a slight angle with the vertical but no usefullight rays pass through this face.

siARCH ROOM At each end of the reading unit, plate-like supporting legsI! and I. are shown castintegral with the lens. This type ofconstruction is for convenience only as the legs may be cemented ormechanically attached. The bottom sides Ila and IBa of these legs reston the paper to be read as does a plane surface II. These threesurfaces, Ia, liar, and I! keep the lens in its proper position and alsoserve in the manner of a. paper weight since they may be used to keep apiece of paper, such as a letter, in the proper plane for reading.

In Fig. 4 the lens rod I I is shown mounted on a reading plane I8. Therays of light from a point 20 on the plane I8 may be traced by followingthe bundle of rays 2| as indicated in the figure. At the first surfaceI3 all the rays are bent to the right and continue through the lens in adirection which is divergent from a point 22 below the plane of thepaper. After traversing the lens block the rays emerge through thecylindrical surface I2 and are refracted again so that they proceed tothe eye as though they originated at the point 23. The degree ofmagnification may be changed by altering the curvature of the exitsurface I2, while the degree of bending may be changed by altering theangle of the prism.

In Figs. 5, 6, and 7 various conditions of illumination are shown andthe results obtained from each are indicated. Fig. 5 shows the readingunit I I and paper plane I8 illuminated by rays of light that come froma point in front of the reader and make an angle of 30 degrees with thehorizontal. Some of the light which strikes the surface I3 will enterthe lens block and travel toward the cylindrical surface I2. However,this light will not be in evidence because most of it will be reflectedfrom surface I2 by total reflection and the remainder will emerge at anangle that will not be seen by the reader.

A large percentage of the light will be directed vertically downward andilluminate the reading plane I8 in an even and satisfactory manner.

Fig. 6 illustrates the reading unit II and paper plane I8 illuminated byrays of light that come from a point in front of the reader but make anangle of 60 degrees with the horizontal. In this condition there is no.reflection from the face I3 and all the illumination on plane I8 isderived from direct radiation.

Fig. 7 shows the reading unit I I and paper plane I8 illuminated by rayswhich come from a source placed almost directly above the glass. All theillumination is due to light which is refracted through the readingglass. The figure illustrates how the rays are directed to the properarea but not in such a concentrated manner as to produce a bad lightspot.

Conventional magnifying glasses of the bullseye type, in contrast, whensubjected to light sources positioned as in Figs. 5-7, yield bright andshadow areas on the reading plane, and the resulting illumination.thereon is not nearly as uniform as obtained with my unit.

The reading unit may be made of any transparent material. In addition toglass, there are several transparent plastics, such as Lucite andPlexiglas, which lend themselves particularly Well to such a use becausethey are light in weight and will not break if dropped on the floor.

While I have described what I consider to be a highly desirableembodiment of my invention, it is obvious that many changes in formcould be made without departing from the spirit of the invention, and I,therefore, do not limit myself to the exact form herein shown anddescribed nor to anything less than the whole of my inventionashereinbefore set forth, and hereinafter claimedr.

I claim:

l. A reading lens comprising a supporting s face for resting on areading plane, a planar surface extending upwardly and rearwardly fromthe rear edge of said supporting surface over the reading matter torefract rays from the reading matter. a second obturating surfaceextending upwardly from the forward edge of said supporting surface, anda curved upper magnifying surface extending downwardly and forwardlybetween said two upwardly directed surfaces.

2. A reading lens comprising a supporting surface for resting on areading plane, a planar surface extending upwardly and rearwardly fromsaid supporting surface at an acute angle of at least twenty degreeswith the reading plane, an upper surface extending forwardly at an acuteangle of at least fifteen degrees with the reading plane, said uppersurface being formed with an integral lens surface for magnifying thereading matter, and an obturating surface extending from the supportingsurface to the upper surface.

3. A prismatic reading lens comprising an inverted prism having a bottomsupporting face for resting on a substantially horizontal reading plane,an inclined face extending upwardly and rearwardly from the bottom faceover the reading matter to refract rays therefrom, an upper faceextending forwardly and downwardly from said inclined face, said upperface being provided with a lens for magnifying the reading matter, andan obturating face extending from the bottom face to the upper face.

4. A fixed focus reading lens comprising a supporting surface forresting on a reading plane, a planar surface extending upwardly andrearwardly from said supporting surface over the reading matter torefract rays therefrom, a curved upper magnifying surface extendingdownwardly and forwardly from said planar surface, an obturating surfaceextending from the supporting surface to the upper surface, andadditional support means to assist said supporting surface inmaintaining the reading lens in stable relationship to the readingplane.

5. A reading lens comprising a supporting surface for resting on areading plane, a planar surface extending upwardly and rearwardly fromsaid supporting surface over the reading matter to refract raystherefrom, a curved upper magnifying surface extending downwardly andforwardly from said. planar surface, an obturating surface extendingfrom the supporting surface to the upper surface and means integrallyformed at an end of said supporting surface forming a continuationthereof rearwardly to assist in supporting the lens from the readingplane.

6. A reading lens comprising a supporting surface elongated from side toside, adapted to rest on a reading plane forward of the reading matter,a planar surface extending upwardly and rearwardly from the rear edge ofthe supporting surface for refracting light rays received from thereading matter, a second obturating surface extending upwardly from theforward edge of said supporting surface, a curved upper surfaceextending downwardly and forwardly between said two upwardly directedsurfaces for magnifying the reading matter, and triangular lugs formedat the sides of said supporting surface in continuation thereofrearwardly over the reading matter and extending upwardly to said planarsurface to prevent tilting of the lens with respect to the read- Numbering plane. 1,701,028

GEORGE M. CRESSATY. 1,908,157 REFERENCES CITED 3 83%? The followingreferences are of record in the 5 2:340:421 file of this patent:

UNITED STATES PATENTS Number Number Name Date 10 204,288 1,600,808Dukehart Sept. 21, 1926 223 35 1,671,272 Buckingham May 29, 1928 SEAKCHROOM Name Date Buckingham Feb. 5, 1929 Walsoe May 9, 1933 Stanley July6, 1937 Bock July 13, 1939 Obrist Feb. 1, 1944 FOREIGN PATENTS CountryDate Great Britain Sept. 27, 1923 Great Britain Feb. 5, 1925

